How do I write an order for a thyroid ultrasound?

How to Write an Order for Thyroid Ultrasound

Order "high-frequency ultrasound of thyroid and central neck" with specific instructions to evaluate nodule characteristics using standardized terminology and include assessment of cervical lymph nodes. 1, 2

Essential Components of the Order

Basic Order Format

• Write: "High-frequency ultrasound of thyroid and central neck" as the primary order 1, 2
• Specify bilateral thyroid evaluation to assess both lobes and the isthmus 3
• Include "with Doppler" if evaluating for thyroiditis or assessing nodule vascularity patterns 2

Required Clinical Information to Include

Indication-specific details:

• State the specific clinical indication (e.g., "palpable thyroid nodule," "abnormal TSH," "family history of thyroid cancer") 2
• Include relevant TSH level if already obtained, as this guides the radiologist's interpretation 2, 4
• Note any history of head/neck irradiation, family history of thyroid cancer, or rapid growth—these are high-risk features that lower the threshold for further intervention 1, 2

Anatomic specifications:

• Request evaluation of "thyroid and central neck (level VI)" to assess for central compartment lymphadenopathy 3
• Add "with lateral neck ultrasound (levels II-V)" if there is clinical suspicion for lymph node involvement or if the nodule is >1 cm with suspicious features 3, 1

Critical Instructions for the Radiologist

Specify nodule characterization requirements:

• Request "characterization using standardized TIRADS terminology" to ensure consistent reporting of suspicious features 1, 5
• Ask for documentation of: composition (solid vs. cystic), echogenicity, margins, presence/absence of microcalcifications, vascularity pattern, and shape (taller-than-wide) 1, 2, 6
• Request measurement of all nodules ≥5 mm in maximal diameter 1

Lymph node assessment:

• Specify "evaluate for suspicious cervical lymphadenopathy" including assessment of size, shape, echogenicity, presence of cystic changes, microcalcifications, and abnormal vascularity 3, 1

Common Clinical Scenarios and Order Modifications

For Known or Suspected Thyroid Nodule

• Standard order: "High-frequency ultrasound of thyroid and central neck with characterization of nodule(s) using TIRADS criteria" 1, 2
• If nodule >1 cm or multiple suspicious features: Add "with lateral neck ultrasound to evaluate for lymphadenopathy" 1

For Thyrotoxicosis (Low TSH)

• Order: "High-frequency Doppler ultrasound of thyroid" to evaluate morphology and vascularity patterns that differentiate Graves disease from destructive thyroiditis 2
• Note: This should be followed by radioiodine uptake scan if etiology remains unclear 2

For Suspected Thyroiditis with Palpable Abnormality

• Order: "High-frequency Doppler ultrasound of thyroid" to differentiate overactive thyroid from destructive thyroiditis and to exclude coexisting malignancy 2

For High-Risk Patients (Radiation History, Family History)

• Order: "High-frequency ultrasound of thyroid, central neck, and bilateral lateral neck" as screening threshold is lower 2
• Explicitly state the risk factor in the indication 2

What NOT to Order

Avoid these common pitfalls:

• Do not order CT or MRI as initial imaging—ultrasound is the only appropriate first-line modality for thyroid nodule characterization 1, 2
• Do not order radioiodine scan in euthyroid patients for malignancy assessment—it does not help determine malignancy risk 2
• Do not order "thyroid scan" when you mean ultrasound—these are different modalities with different indications 2

Follow-Up Based on Results

If ultrasound reveals nodule ≥1 cm with suspicious features:

• Next step is ultrasound-guided fine-needle aspiration (FNA) of the nodule and any suspicious lymph nodes 1
• Suspicious features include: microcalcifications, marked hypoechogenicity, irregular margins, absence of halo, central hypervascularity, or taller-than-wide shape 1, 2, 6

If nodule <1 cm:

• FNA is indicated only if ≥2 suspicious ultrasound features plus high-risk clinical factors (radiation history, family history, suspicious lymphadenopathy) 1, 2
• Otherwise, surveillance is appropriate 1